Central United States. Range extends north to Canada, south to Texas, east to Iowa, and west to Idaho.
Terrestrial. Generally occur in dry areas with moderate foliage. Found in rocky areas, grasslands, prairies, and forests.
Venomous, considered dangerous to humans. Adult length 35-45 inches. Occurs in shades of grey, brown, or green. Occasionally light brown or yellowish in color. All individuals have greenish-grey blotches, wide triangular head, thin neck, and blunt tail with a rattle. Vertical pupils and pits on each side of head & below each nostril.
Learn more with Schechter Natural History's Guide to Reptiles and Amphibians